Yarn and method of making same



P 1968 A. RICHMOND ETAL 3,380,242

YARN AND METHOD OF MAKING SAME Filed Feb. 11, 1958 2 Sheets-Sheet l '23/20 v I /5 k 25 mmg-wfors A/frec/ Rwhmopd ROber/A/berf K/ng A /ex0nderHenderson Gem/e P 30, 1963 A. mcumouo ETAL 3,380,242

YARN AND METHOD OF MAKING SAME Filed Feb. 11, 1958 2 Sheets-Sheet 2/nven/0r$ A/fred Man/770m Robe/f A /0 en K/ng A /ex0nde/ HendersonGen/7e By Dav/s, Hox/, fbi/hful/ 8 Hapgood Afforneys Uited States PatentO 3,386,242 YARN AND METl-ifil) OF MAKING SAME Alfred Richmond, RobertAlbert King, and Alexander Henderson Gentle, Spondon, near Derby,England, assignors, by mesne assignments, to American Erika Corporation,Erika, N.C., a corporation of Delaware Filed Feb. 11, $58, Ser. No.714,601 Claims priority, application Great Britain, Mar. 1, 1957,6,876/5'7 3 Claims. {57-146) This invention relates to the production ofvoluminous yarn and more particularly to a method in which a yarn,especially a continuous filament yarn, is subjected to the action of aturbulent stream of fluid, the resulting yarn, and fabrics madetherefrom, having a characteristic appearance and handle similar tothose of a staple fibre yarn. The term yarn is used as includinguntwisted bundles of filaments as well as products containing twist.

According to the present invention, in subjecting a yarn to the actionof a turbulent stream of fluid for the purpose stated, a hot gaseousfluid is used with the object of increasing the degree of permanence ofthe loops and sinuosities imparted to the individual filaments of theyarn by the action of the turbulent stream. It has been found that,although it is still desirable that the resulting yarn should have somedegree of twist to lock the loops and convolutions of the filaments, itis possible to use a lower degree of twist for this purpose. Moreover,it has been found possible to produce yarns in which the sinuosities ofthe individual filaments exposed on the yarn surface are more numerousand more evenly distributed through the length and body of the yarn butare of less exaggerated form,'being rather arch-like, or of the natureof deep waves, than of complete ringlike loops. it appears possible thatthe softening effect of the hot gaseous medium enables the sinuositiesof the filaments to be retained through the critical period betweentheir formation and their being locked into the yarn by such twist as isemployed for this purpose, thus retaining in the final yarn a degree ofvoluminosity, which with the use of a cold fluid stream is momentarilyimparted to the yarn but is for the most part lost before it can belocked into the yarn.

While, in general, any hot gaseous medium may be employed for thepurposes of the invention, it is clearly undesirable to use gases liableto produce a chemical reaction on the yarn or upon the apparatusemployed. Indeed, for this purpose, it is better to avoid the use evenof hot air, the oxygen content of which might tend to discolor the yarn,though there appears to be no reason why a hot inert gas, particularlynitrogen, should not be employed. However, the preferred gaseous mediumis steam, particularly moist steam, since the presence of moisture inmost cases reduces the temperature to which the gaseous medium needs tobe heated to produce the desired effect. Accordingly, the invention isdescribed hereafter with particular reference to moist steam.

The invention is applicable generally to yarns of continuous filamentsof materials susceptible to the influence of heat, with or withoutmoisture, for imparting to them some degree of permanence of the form inwhich they are so treated, and this includes most textile materials. Theinvention is particularly applicable, however, to thermoplasticmaterials, such as acetone-soluble or other cellulose acetate or otherorganic derivatives of cellulose, copolymers of vinyl chloride and vinylacetate, and acrylonitrile polymers and copolymers of acrylonitrile withmoderate proportions of other vinyl compounds. The invention is mostespecially applicable, however, to yarn of filaments of materials whichare capable of heatsettrng, such as cellulose acetate of acetyl value atleast 59 percent calculated as acetic acid (hereinafter referred to ascellulose triacetate), copolymers containing a substantial proportion ofvinylidene chloride, polyaminocaproic acid, polyhexamethylene adipamideand polyethylene terephthalate, which substances appear, at hightemperatures short of their melting points, to be subject to an increasein crystallinity, whereby the form in which they are treated isstabilised and rendered more nearly permanent. Yarns of cellulosetriacetate filaments may be such as have been made by wet-spinning,dry-spinning or melt-spinning processes.

The yarn is subjected for the purposes of the present invention to theaction of a turbulent stream by passing it through a suitable form ofjet to which the hot gaseous medium is supplied. The yarn is thus passedthrough a turbulent zone of the hot gaseous fluid. A form of jetparticularly suitable for the purpose is that described in US.application Serial No. 540,596, W. Pool, filed October 14, 1955, nowPatent No. 2,982,082, in which an inlet tube for the entry of the yarninto the jet extends through a chamber within the jet and is providedwith a tip facing and entering the mouth of a venturi through which theyarn and the hot gaseous stream leave the jet, the venturi and the outersurfaces of the tip being so shaped that a fluid stream blown underpressure into the chamber will create a vortex beyond the tip of theinlet. Such a jet can be used, if desired, in conjunction with thebaffle plate described in US. Application Serial No. 356,349, filed May21, 1953, now Patent N0. 2,942,402, or the jet described in thatapplication, with a battle, may be used. Or again, the jet described iscopending US, application of A. Richmond, W. Pool and A. H. Gentle,Serial No. 714,602- filed February 11, 1958, now Patent No. 3,010,270,may be employed.

The moist steam may be supplied to the jet employed at a wide variety ofpressures, ranging from about 15 lb. gauge pressure up to lb. or more(according to the speed of travel of the yarn and the intensity oftreatment desired) corresponding to a steam temperature of -170 C. ormore. Where dry steam, or other dry hot gas is employed highertemperatures will generally be necessary, e.g. up to 250 or more butshort, of course, of the melting point of the filaments. With such gasesthe supply pressure can be adjusted to a value, preferably the minimumvalue, which will give the desired degree of voluminosity to theemergent yarn. With moist steam, however, the pressure may be dictatedby the temperature requirements and may be greater than is necessary togive the desired degree of voluminosity, which will then be determinedby the relative speeds of input and drawoff of the yarn into and fromthe jet.

The input and draw-off arrangements, by which the degree of voluminositymay be controlled, may comprise two sets of yarn driving rollers, namelyfeed rollers and draw-off rollers of different speeds and/ or diametersproviding the required amount of overfeed. Alternatively, a singleroller may be used with tWo portions of differing diameter, the yarnpassing from the portion of larger diameter to the jet inlet and backfrom the jet outlet to the portion of smaller diameter. The feed rollersmay take the yarn over-end from a stationary package, or from one whichis rapidly rotated, or from a package mounted on a double twist spindle,to impart twist to the yarn additional to that (if any) already in theyarn. From the draw-oil rollers the yarn may be led to a suitable takeupdevice, preferably driven at a constant peripheral speed equal to orslightly lower than that of the draw-off rollers. Alternatively, whereit is desired to impart locking-twist, or further locking-twist to theyarn the yarn may be supplied from the draw-off rollers to a twistingspindle where such twist is imparted to the yarn as it is collected.

If desired, two or more yarns may be treated by passing them togetherthrough the jet. Depending on. the conditions employed and also on thetwist and/ or other characteristics of the yarns, the latter may beseparated after treatment and wound separately. Alternatively, theproduct may be such that, owing to entanglement of the filaments of oneyarn with those of another, separation is not possible.

By way of example, an apparatus for the production of voluminous yarn,and the method of using it in accordance with the present invention willbe described in more detail with reference to the drawings in which:

FIG. 1 is a cross section of a jet suitable for treatment of afilamentary bundle in accordance with the invention.

FIG. 2 shows diagrarnatically a general arrangement of jet andassociated filament feed and take-up devices.

FIGURE 3 is a schematic drawing greatly enlarged of a yarn according tothe invention.

The apparatus comprises a jet unit of the general type described in theabove application Ser. No. 540,596, now

Patent No. 2,982,082. The jet unit as shown in FIG. 1

and indicated at in FIG. 2, comprises a T-piece 11, the double limb 12of which communicates at each end with the atmosphere, while the thirdlimb 13 is connected to a steam header 14 for the supply of steam to theunit. Within the double limb 12 is slipped a cylindrical member 15 whichis circumferentially grooved about one-quarter and three-quarters wayalong its length for the reception of rings 16 of suitable packingmaterial adapted to make a tight joint against the wall of the doublelimb. Into one end of the cylindrical member is slipped a tubular yarninlet member 17, the tip 18 of which is of double-conical form, havingconical angles of 47 near the tip and 33 a short distance behind thetip. The inlet has an entry bore 19 of A3", which tapers to X at thetip. At the other end of the cylindrical member 15 is inserted a venturitube 20 having an inlet cone 21 of 40 angle, a throat diameter 22 of andan outlet cone 23 of 10 angle, the tip 18 of the inlet jet entering intothe inlet cone 21 of the venturi. Both the inlet jet 17 and the venturitube 20 are externally flanged to engage against the ends of thecylindrical member 15 and are held in place by two collars 24, 25internally flanged to engage over the external flanges of the inlet jet17 and venturi 20 respectively, and internally screw-threaded to screwover the cylindrical member 15. The inner edges of the collars 24, 25engage the packing rings 16 and compress them against the wall of thedouble limb 12 of the T-piece 11, so holding the whole assembly inplace. Mid-way along its length the cylindrical member 15 is bored withdiametrically opposite holes 26 for the admission of steam entering fromthe steam main 14 through the third limb 13 of the T-piece 11. A gauzecollar 27 may be provided surrounding the middle portion of thecylindrical member 15.

Yarn 29 is fed into the inlet of the jet 10 from a stationary orrotatable package 30 by means of a pair of feed rollers 31, 32 disposedparallel to and beneath the steam main 14, and is taken up as it leavesthe venturi outlet of the jet by a second pair of rollers 33, 34delivering the treated yarn 29a via a guide rod 35 to a drumdrivencheese winder in which a driving drum 36 drives the cheese of yarn 37,the yarn being guided by the traverse guide 38. The feed rollers 31, 32are driven at a somewhat higher speed than the delivery rollers 33, 34so as to give the required overfeed, and steam at the appropriatepressure is supplied to the steam main 14 and thence to the jet 10through which the yarn passes. The steam serves a series of jet unitssupplied by feed and delivery rollers each driven by a common shaft.

From FIGURE 3 it will be seen that in yarn according to the inventionthe individual filaments, while physically separate and unbonded, areentangled with one another. Each has a curvilinear, sinuous,three-dimensional crimp which is randomly distributed along its length.The crimp may be fixed by the crystalline structure developed by heatsetting, as noted above, and is substantially free from ringlike loops.

The invention is illustrated by the following examples. In Examples I toIII treatment is effected using the apparatus described above withreference to the drawings.

EXAMPLE I A dry spun yarn of cellulose triaceta-te (acetyl value 61percent measured as acetic acid) consisting of 50 continuous filamentsof a total denier of 200, and having 5 turns per inch Z twist is drawnover-end from a supply package rotating at 8,000 revolutions per minuteto increase the twist. The feed rollers are driven at a speed of 55 yd.per minute and supply the yarn to the inlet of the jet. Steam issupplied to the jet at a gauge pressure of 30 lb. per sq. in. C.) andthe yarn is drawn out by the draw-oil? rollers at 50 yd. per minute andwound into a cheese. The resulting yarn has a denier of 240 and a twistof 10 turns per inch Z, and is of a bulky character, exhibiting a fewringlike loops on its surface at intervals along its length but a muchgreater number of archlike loops.

EXAMPLE II A continuous filament melt spun yarn of cellulose triacetateof a nominal total denier of 700, is made by doubling to 2.5 turns perinch S twist two yarns each consisting of 30 continuous filaments of atotal denier of 350 and a singles twist of 3.5 turns per inch Z. Thedoubled yarn is drawn over-end from a stationary supply bobbin at 40 yd.per minute and fed into the jet, which is supplied with steam at 60 lb.per sq. in. (153 C.). The resulting yarn had a total denier of about 900and is very bulky in character exhibiting a large number of archlikeloops and practically no ringlike loops.

EXAMPLE III A heavy yarn of continuous filaments of polyaminocaproicacid, consisting of filaments twisted together to 2 /2 turns per inchand having a total denier of 6,800 is drawn over-end from a supplypackage at 44 yards per minute and fed to the jet which is supplied withsteam at 90 lb. per sq. in. C.), the resulting yarn being taken-up at 33yd. per minute and having a total denier of about 8,800. The resultingyarn is very bulky and woollike in character and is suitable for use asthe pile yarn in the manufacture of a tufted carpet.

EXAMPLE IV In this example the apparatus used is similar to that usedaccording to Examples I to III except that the jet is replaced by thatshown in FIG. 1 of the drawings of copending application Ser. No.714,602 filed Feb. 11, 1958, of A. Richmond, W. Pool and A. H. Gentle,now Patent No. 3,010,270. Further the yarn feed and yarn collectingarrangements are duplicated so that two yarns can be fed through thejet.

A yarn is prepared by doubling together, with 3.5 turns per inch Ztwist, three ends of acetone-soluble cellulose acetate yarn each of 750denier and 50 filaments and I turn per inch S twist. Two such yarns arefed together at an input speed of 40 metres per minute to the jet whichis supplied with saturated steam at 80 lbs. per sq. in. The two yarnsare withdrawn at 30 metres per minute, separated, and wound on toseparate cones. Each bulked and concd yarn has a final denier of about2,600.

EXAMPLE V Three ends of 0.5 turns per inch Z twist 600 denier 40filament of melt-spun cellulose acetate of acetyl value about 61 percentcalculated as acetic acid are doubled together with 3.5 turns per inch Stwist; three of the doubled yarns are then twisted together with 3 turnsper inch Z twist to form a yarn of about 5,500 total denier. This heavyyarn is then run through the apparatus shown in FIG. 2 of the drawingsof co-pending U.S. application Ser. No. 714,602, filed Feb. 11, 1958,now Patent No. 3,010,270, using the jet shown in FIG. 1 and thecollecting arrangement shown in FIG. 3. The jet is supplied withsaturated steam at 80 lbs. per sq. in. pressure, the yarn input speed is40 metres per minute and the yarn output speed 27.5 metres per minute.The resulting yarn is very suitable for forming the pile of a carpet.

What we claim is:

1. The process of imparting a persistent crimp to synthetic linearpolymeric filaments and yarns which comprises feeding the same to aplasticizing stream of a compressible fluid having a temperature of atleast about 300 F. in which the individual filaments, while in a plasticstate and under substantially zero tension, are separated from eachother and crimped individually While whipping about in the turbulentplasticizing stream, the crimp having a random, three-dimensional,curvilinear, extensible configuration, and setting the crimp therebyimparted to the said filaments.

2. A process for making a multi-filament yarn the individual filamentsof which have a highly persistent crimp with a sinuous, curvilinear,three-dimensional, extensible configuration randomly disposed along thelength of the filaments, said process comprising subjecting, under sub-25 stantially zero tension, a yarn of continuous thermoplastic filamentscapable of heat setting, to a turbulent stream of a compressible fluidhaving a temperature sufficient to set said filaments, and therebysetting said filaments in a sinuous, curvilinear, three-dimensional,extensible, random crimp imposed upon them by said turbulent stream.

3. A continuous filament yarn comprising a plurality of entangled bu-tphysically separate filaments, each of said filaments being individuallypermanently fixed by a crystalline molecular structure in a persistent,random, three-dimensional, sinuous, curvilinear, extensible crimp andbeing substantially free from ring-like loops.

References Cited UNITED STATES PATENTS 2,435,891 2/ 1948 Lodge 28-72 XR2,783,609 3/1959 Bree 57-157 XR 2,807,862 10/1957 Griset 28-72 2,852,9069/1958 Breen 57-34 2,869,967 1/1959 Breen 57-140 2,379,824 7/1945Mummery 57-34 2,584,043 1/1952 Oberly 57-34 2,815,559 12/ 1957 Robinson.

2,962,794 12/ 1960 Field 28-72 XR 3,009,309 11/1961 Breen et a1 57-139MERVIN STEIN, Primary Examiner.

RUSSELL C. MADER, Examiner.

I. B. MAIER, Assistant Examiner.

1. THE PROCESS OF IMPARTING A PERSISTENT CRIMP TO SYNTHETIC LINEAR POLYMERIC FILAMENTS AND YARNS WHICH COMPRISES FEEDING THE SAME TO A PLASTICIZING STREAM OF A COMPRESSIBLE FLUID HAVING A TEMPERATURE OF AT LEAST ABOUT 300*F. IN WHICH THE INDIVIDUAL FILAMENTS, WHILE IN A PLASTIC STATE AND UNDER SUBSTANTIALLY ZERO TENSION, ARE SEPARATED FROM EACH OTHER AND CRIMPED INDIVIDUALLY WHILE WHIPPING ABOUT IN THE TURBULENT PLASTICIZING STREAM, THE CRIMP HAVING A RANDOM, THREE-DIMENSIONAL, CURVILINEAR, EXTENSIBLE CONFIGURATION, AND SETTING THE CRIMP THEREBY IMPARTED TO THE SAID FILAMENTS.
 3. A CONTINUOUIS FILAMENT YARN COMPRISING A PLURALITY OF ENTANGLED BUT PHYSICALLY SEPARATE FILAMENTS, EACH OF SAID FILAMENTS BEING INDIVIDUALLY PERMANENTLY FIXED BY A CRYSTALLINE MOLECULAR STRUCTURE IN A PERSISTENT, RANDOM, THREE-DIMENSIONAL, SINUOUS, CURVILINEAR, EXTENSIBLE CRIMP AND BEING SUBSTANTIALLY FREE FROM RING-LIKE LOOPS. 